|number = Ordinal number of the Congress, i.e, "1st" in 1st United States Congress
|previous = Ordinal number of the previous Congress
|next = Ordinal number of the next Congress
|image = File name of image (optional). The default is a recent photo of the U.S. Capitol.
|imagename = Date of the image (optional). The default is [[United States Capitol]].
|imagedate = Date of the image (optional).
|start = First possible day of the Congress (not necessarily the first day of the first session)
|end = Last possible day of the Congress (not necessarily the last day of the last session)
|sessionstart1 = First day of the first session
|sessionend1 = Last day of the first session (i.e., day the last house adjourned sine die)
|sessionstart2 = First day of the second session (optional)
|sessionend2 = Last day of the second session (optional)
|sessionstart3 = First day of the third session (optional)
|sessionend3 = Last day of the third session (optional)
|sessionstart4 = First day of the fourth session (optional)
|sessionend4 = Last day of the fourth session (optional)
|specialsessionstart1 = First day of the first SPECIAL session (optional)
|specialsessionend1 = Last day of the first SPECIAL session (optional)
|specialsessionstart2 = First day of the second SPECIAL session (optional)
|specialsessionend2 = Last day of the second SPECIAL session (optional)
|vp = President of the Senate (Vice President of the United States)
|pro tem = President pro tempore of the Senate
|speaker = Speaker of the House
|senators = Total number of Senators, including vacancies
|reps = Total number of Representatives, including vacancies
|delegates = Same for delegates (whatever called) from territories, etc. (optional)
|s-majority = Majority party in the Senate
|h-majority = Majority party in the House